Caterpillar treadmill

ABSTRACT

A tread assembly includes two belts and many slats. Each belt includes apertures. Each slat includes a rigid element, two threaded bolts and a cushion. The rigid element includes two apertures, an external face, and an internal face in contact with the belts. Each of the threaded bolts includes a middle section and two terminal sections. The middle section is inserted in one of the apertures of the rigid element so that the threaded bolts cannot be rotated relative to the rigid element. The first terminal section is located on the external face of the rigid element. The second terminal section is inserted in one of the aperture of a one of the belts. The cushion includes an internal face in contact with the external face of the rigid element and an external face extending higher than the first external section of each of the threaded bolts.

BACKGROUND OF INVENTION 1. Field of Invention

The present invention relates to a treadmill and, more particularly, to a tread assembly of a treadmill.

2. Related Prior Art

China Patent Application Publication No. 105688369 discloses a treadmill includes a frame 1 and a tread assembly. The tread assembly includes two belts 6 and a number of slats 23. Each of the belts 6 is in the form of a loop. Each of the slats 23 includes a terminal section 24 connected to one of the belts 6 by a screw and another terminal section 24′ connected to the other belt 6 by another screw. Each of the screws includes a sharp tip and a flat head. Each of the screws is inserted in a corresponding one of the belts 6, from an internal face. However, the tip of each of the screws inevitably causes a bump on an external face of the corresponding belt 6 as shown in FIG. 2. Alternatively, each of the screws is inserted in each of the belts 6, from the external face. However, the head of each of the screws inevitably extends beyond the internal face of the corresponding belt 6. The bumps or the heads of the screws could trip a user, and this is not desired.

The present invention is therefore intended to obviate or at least alleviate the problems encountered in prior art.

SUMMARY OF INVENTION

It is the primary objective of the present invention to provide a treadmill with a safe tread assembly.

To achieve the foregoing objective, the tread assembly includes two belts and many slats. Each of the belts includes apertures. Each of the slats includes a rigid element, two threaded bolts and a cushion. The rigid element includes two apertures, an external face, and an internal face in contact with the belts. Each of the threaded bolts includes a middle section and two terminal sections. The middle section is inserted in one of the apertures of the rigid element so that the threaded bolts cannot be rotated relative to the rigid element. The first terminal section is located on the external face of the rigid element. The second terminal section is inserted in one of the aperture of a one of the belts. The cushion includes an internal face in contact with the external face of the rigid element and an external face extending higher than the first external section of each of the threaded bolts.

Other objectives, advantages and features of the present invention will be apparent from the following description referring to the attached drawings.

BRIEF DESCRIPTION OF DRAWINGS

The present invention will be described via detailed illustration of the preferred embodiment referring to the drawings wherein:

FIG. 1 is a partial perspective view of a treadmill according to the preferred embodiment of the present invention;

FIG. 2 is a cross-sectional view of the treadmill shown in FIG. 1;

FIG. 3 is an enlarged partial exploded view of a tread assembly of the treadmill shown in FIG. 1;

FIG. 4 is an enlarged partial cut-away view of the tread assembly shown in FIG. 3;

FIG. 5 is an enlarged partial cross-sectional view of the tread assembly shown in FIG. 3; and

FIG. 6 is an enlarged partial side view of the treadmill shown in FIG. 1.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENT

Referring to FIGS. 1, 2 and 6, a treadmill 10 includes a frame 11 and a tread assembly 20 according to the preferred embodiment of the present invention. The treadmill 10 includes a frame 11 that includes a base 12. The base 12 is made of at least two longitudinal rods (not numbered) connected to at least two transverse rods (not numbered).

The base 12 further includes two axles 13, two pairs of bearings 14, a pair of drums 15, a pair of leader pulleys 16, a pair of follower pulleys 17, a belt 18 and a motor 19. The axles 13 extend parallel to each other. Each of the axles 13 includes two terminal sections supported on the base 12. Each of the drums 15 is supported on a corresponding axle 13 by a corresponding pair of bearings 14 so that the drums 15 are rotatable around the axles 13. The pair of leader pulleys 16 is attached to one of the drums 15. Each of the leader pulleys 16 is formed with teeth 161. The pair of follower pulleys 17 is connected to the other drum 15. Although not shown, each of the follower pulleys 17 is formed with teeth like each of the leader pulleys 16 does. The motor 19 is secured to the base 12 or another proper portion of the frame 11. The motor 19 includes a mandrel 191. The mandrel 191 is connected to one of the leader pulleys 16 via the belt 18.

Referring to FIGS. 1 and 2, the tread assembly 20 includes two flexible belts 21 and a number of slats 22. Each of the belts 21 is in the form of a loop. Each of the slats 22 is connected to the belts 21 by a fastener assembly 23. The tread assembly 20 is supported on and around the leader pulleys 16 and the follower pulleys 17. The motor 19 is located in the tread assembly 20.

Referring to FIGS. 3 to 6, each of the belts 21 includes an external face in contact with the slats 22 and an internal face opposite to the external face. The external face of each of the belts 21 is flat. The internal face of each of the belts 21 is not flat so that each of the belts 21 is made with a thick portion 24 and a thin portion 25, and teeth 26 are formed on the internal face of the thin portion 25. There is a valley 27 between any two adjacent teeth 26. The teeth 26 are engaged with the teeth 161 of the leader pulleys 16 and the teeth of the follower pulleys 17 so that the belts 21 are movable together with the leader pulleys 16 and the follower pulleys 17 (FIG. 2).

Each of the fastener assemblies 23 includes two threaded bolts 35, a washer 36 and two nuts 38. The threaded bolts 35 are inserted in two apertures 28 made in the belt 21 and two apertures 37 made in the washer 36 and engaged with the nuts 38. The washer 36 is an arched element that covers a corresponding one of the teeth 26, without affecting the engagement of the corresponding tooth 26 with a corresponding one of the teeth 161.

In the preferred embodiment, each of the threaded bolts 35 includes a polygonal section 352, the polygonal section 352 formed between a head 351 and a threaded section 353. In another embodiment, each of the threaded bolts 35 can be a carriage bolt.

Each of the slats 22 includes a cushion 31 that covers a rigid element 30. The rigid element 30 includes an aperture 301 made in each of two terminal sections thereof. The polygonal section 352 of each threaded bolt 35 is inserted in a corresponding aperture 301. The head 351 of each threaded bolt 35 is located on an external face of the rigid element 30 while the threaded section 353 of the same is located on an internal face of the rigid element 30. Each of the apertures 301 includes a polygonal wall in contact with the polygonal section 352 of the corresponding threaded bolt 35 so that the threaded bolts 35 is not rotated relative to the rigid element 30 in a process of engaging each nut 38 with the corresponding threaded bolt 35.

The threaded section 353 of each threaded bolt 35 extends beyond the internal face of the rigid element 30. The threaded section 353 of each threaded bolt 35 extends beyond the external face of the rigid element 30. However, an external face of the cushion 31 is located higher than the head 351 of each threaded bolt 35. That is, the head 351 of each threaded bolt 35 does not extend beyond the external face of the cushion 31. Thus, the cushion 31 keeps the threaded section 353 of each threaded bolt 35 from tripping a user.

The external face of the cushion 31 is an anti-skid face 311. To this end, the anti-skid face 311 is made with bosses, ridges and/or grooves.

The present invention has been described via the illustration of the preferred embodiment. Those skilled in the art can derive variations from the preferred embodiment without departing from the scope of the present invention. Therefore, the preferred embodiment shall not limit the scope of the present invention defined in the claims. 

1. A tread assembly comprising: two belts (21) each of which comprises apertures (28); and slats (22) each of which comprises: a rigid element (30) comprising two apertures (301), an external face, and an internal face in contact with the belts (21); two threaded bolts (35) each of which comprises: a middle section (352) inserted in one of the apertures (301) of the rigid element (30) so that the threaded bolts (35) cannot be rotated relative to the rigid element (30); a first terminal section (351) located on an external face of the rigid element (30); and a second terminal section (353) inserted in one of the aperture (28) of one of the belts (21); and a cushion (31) comprising an internal face in contact with the external face of the rigid element (30) and an external face extending higher than the first external section (351) of each of the threaded bolts (35).
 2. The tread assembly according to claim 1, wherein the apertures (301) of the rigid element (30) are polygonal apertures, wherein the middle section (352) of each of the threaded bolts (35) is a polygonal section inserted in the apertures (301) of the rigid element (30) so that the threaded bolts (35) are not rotatable relative to the rigid element (30).
 3. The tread assembly according to claim 2, wherein the first terminal section (351) of each of the threaded bolts (35) is an enlarged head that does not extend beyond the external face of the cushion (31).
 4. The tread assembly according to claim 2, wherein the second terminal section (353) of each of the threaded bolts (35) is a threaded section.
 5. The tread assembly according to claim 1, wherein the threaded bolts (35) are carriage bolts.
 6. The tread assembly according to claim 1, wherein the external face of the cushion (31) is an anti-skid face (311). 